diff --git a/cocos2dx/CCDirector.cpp b/cocos2dx/CCDirector.cpp
index fcf2c435b5..ddf3387ef6 100644
--- a/cocos2dx/CCDirector.cpp
+++ b/cocos2dx/CCDirector.cpp
@@ -46,6 +46,7 @@ THE SOFTWARE.
 #include "CCGL.h"
 #include "CCAnimationCache.h"
 #include "CCTouch.h"
+#include "CCUserDefault.h"
 
 #if CC_ENABLE_PROFILERS
 #include "support/CCProfiling.h"
@@ -569,6 +570,7 @@ void CCDirector::purgeDirector()
 	CCActionManager::sharedManager()->purgeSharedManager();
 	CCScheduler::purgeSharedScheduler();
 	CCTextureCache::purgeSharedTextureCache();
+	CCUserDefault::purgeSharedUserDefault();
 
 	// OpenGL view
 	m_pobOpenGLView->release();
diff --git a/cocos2dx/include/CCUserDefault.h b/cocos2dx/include/CCUserDefault.h
index e664c51285..59bb034bbc 100644
--- a/cocos2dx/include/CCUserDefault.h
+++ b/cocos2dx/include/CCUserDefault.h
@@ -35,7 +35,7 @@ NS_CC_BEGIN;
 class CC_DLL CCUserDefault
 {
 public:
-	~CCUserDefault() {}
+	~CCUserDefault();
 
 	// get value methods
 	bool	getBoolForKey(const char* pKey);
@@ -52,6 +52,7 @@ public:
 	void	setStringForKey(const char* pKey, std::string value);
 
 	static CCUserDefault* sharedUserDefault();
+	static void purgeSharedUserDefault();
 	const static std::string& getXMLFilePath();
 
 private:
diff --git a/cocos2dx/platform/android/CCFileUtils_android.cpp b/cocos2dx/platform/android/CCFileUtils_android.cpp
index d4fd123d40..8637e74b66 100644
--- a/cocos2dx/platform/android/CCFileUtils_android.cpp
+++ b/cocos2dx/platform/android/CCFileUtils_android.cpp
@@ -104,7 +104,7 @@ int CCFileUtils::ccLoadFileIntoMemory(const char *filename, unsigned char **out)
     return 0;
 }
 
-const string CCFileUtils::getWriteablePath()
+string CCFileUtils::getWriteablePath()
 {
 	// the path is: /data/data/ + package name
 	string dir("/data/data");
diff --git a/cocos2dx/platform/win32/CCFileUtils_win32.cpp b/cocos2dx/platform/win32/CCFileUtils_win32.cpp
index d6de05c785..891f381e19 100644
--- a/cocos2dx/platform/win32/CCFileUtils_win32.cpp
+++ b/cocos2dx/platform/win32/CCFileUtils_win32.cpp
@@ -163,7 +163,7 @@ void CCFileUtils::setRelativePath(const char* pszRelativePath)
     CCAssert(0, "Have not implement!");
 }
 
-const string CCFileUtils::getWriteablePath()
+string CCFileUtils::getWriteablePath()
 {
 	// return the path that the exe file saved in
 
diff --git a/cocos2dx/support/CCUserDefault.cpp b/cocos2dx/support/CCUserDefault.cpp
index 995f9e863b..8423abca3c 100644
--- a/cocos2dx/support/CCUserDefault.cpp
+++ b/cocos2dx/support/CCUserDefault.cpp
@@ -133,6 +133,21 @@ CCUserDefault* CCUserDefault::m_spUserDefault = 0;
 string CCUserDefault::m_sFilePath = string("");
 bool CCUserDefault::m_sbIsFilePathInitialized = false;
 
+/**
+ * If the user invoke delete CCUserDefault::sharedUserDefault(), should set m_spUserDefault
+ * to null to avoid error when he invoke CCUserDefault::sharedUserDefault() later.
+ */
+CCUserDefault::~CCUserDefault()
+{
+	m_spUserDefault = NULL;
+}
+
+void CCUserDefault::purgeSharedUserDefault()
+{
+	CC_SAFE_DELETE(m_spUserDefault);
+	m_spUserDefault = NULL;
+}
+
 bool CCUserDefault::getBoolForKey(const char* pKey)
 {
 	const char* value = getValueForKey(pKey);